1. Technical Field of Use of the Invention
The invention relates to a safety key and locking cylinder, the locking cylinder having a stator and a rotor, with a front end and a rear end, and a keyway, and the safety key having a shank which is provided with a plurality of control surfaces for properly positioning tumblers and has a front end and a rear end. The invention also relates to a locking system with such safety keys and locking cylinders.
2. Prior Art
Safety keys and locking cylinders of the above-mentioned type are known in numerous configurations. The essential factor for safety keys for high-grade systems is for there to be no possibility of straightforward copying on comparatively simple drilling and milling machines. A safety key which is difficult to copy may be achieved in accordance with the applicant's EP 0 621 384 B1 by the shank of the safety key being provided with a control element which is designed as a pin and is mounted in a displaceable manner in the shank. This control element can be properly positioned by an additional tumbler in the locking cylinder. Such a key cannot be copied with justifiable outlay. A so-called toothed key with a similar control element has been disclosed in EP 0 802 289. It is also ensured that this key is comparatively difficult to copy.
The abovementioned safety key is rendered disadvantageous by the costs which arise from the formation of the abovementioned control elements and from the additional tumblers in the locking cylinder. These control elements, in addition, may have an adverse effect on the combinatorics.